TagHandlerPool is slow when I ran stress test my web application using tomcat7.
It occured in 7.0.19.
Profiler said that it causes are followings:
1. Lock of log instance at org.apache.jasper.runtime.TagHandlerPool.
2. Lock of parameters field at org.apache.catalina.core.StandardWrapper.getInitParameter.
An attached patch resolve this issue in my environment.
It makes following changes:
1. Makes log field to static.
2. At StandardWrapper, changes lock policy from synchronized block to ReentrantReadWriteLock.

The lock changes look good to me.
The log change needed more careful checked. I have vague recollections of memory leaks with Jasper and logging and a number of components using non-static loggers to avoid them. Having checked the initialisation sequence, the logger is created by the container class loader, not a web app class loader so that change should be fine to. I'll commit these changes shortly.

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